Variability of cerebral hemoglobin concentration in very preterm infants during the first 6 hours of life.

Cerebral hemoglobin concentration (cHbc), a major determinant of oxygen transport capacity in the brain, shows a considerable variability due to physiological and methodological factors. In order to determine the (relative) contribution of these factors, the cHbc variability within the first 6 hours of life was studied in 28 very preterm infants using near infrared spectrophotometry (NIRS). Mean cHbc values were 46.

Predictors of adverse outcome in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy: long term experience of a tertiary care centre.

Objective: To investigate the predictors for adverse clinical outcome in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) during long term follow up.

Methods: 61 patients with ARVD/C were studied to assess the impact of family history, clinical findings, surface ECG parameters, echocardiographic findings, and electrophysiological findings on clinical outcome. The prevalence of these risk factors were compared in two patient groups: group A (patients with adverse clinical outcome: sudden cardiac death, death from heart failure, or heart transplant) and group B (survivors excluding patients who received a heart transplant).

Effect of 1000 ppm relative to 250 ppm fluoride toothpaste. A meta-analysis.

Purpose: To estimate the overall effect of 1000 ppm F relative to 250 ppm F toothpaste.

Methods: Experimental caries increment studies from the dental literature, which compared 1000 ppm with 250 ppm fluoride toothpastes, were summarized using meta-analytic methods.

Results: The overall caries reduction of 1000 ppm F relative to 250 ppm F paste was estimated to be 0.

[Caries prevalence among students in 16 Zurich districts in the years 1992 to 2000].

Standardized dental examinations of schoolchildren were regularly carried out since 1964 in 16 rural communities of the Canton of Zurich. In 1964, there were no 14-year-old schoolchildren free from caries; in the Nineties about half of the 14-year-olds had a caries-free permanent dentition (DMFT = 0). From the year 1992 to 2000, the caries prevalence (DMFT) of 14-year-olds decreased once again, by 31%.

An example of complex modelling in dentistry using Markov chain Monte Carlo (MCMC) simulation.

Background: In the usual regression setting one regression line is computed for a whole data set. In a more complex situation, each person may be observed for example at several points in time and thus a regression line might be calculated for each person. Additional complexities, such as various forms of errors in covariables may make a straightforward statistical evaluation difficult or even impossible.